(noun)
An attention-craving individual that -- in an issue or debate -- takes whatever side makes him or her look good & open-minded to the public, without regard to the details or the truth in the issue debated. A GOMP is different from an SJW because the issue does not have to be social.

(verb)
To make a public statement on an issue without really understanding the details or the truth of the issue, just to show off to the world how good & open-minded one is.

(noun) "Justin was just being a GOMP when he tweeted his support for adopting dogs from shelters, especially since he bought his dog from a pet store."

(verb) "Fred GOMPed his support for the Invisible Children all over social media."

Any mentally retarded person.
Usually the word implies the retarded person is profoundly retarded and leaking fluids such as spittle, has cake between their fingers, spaghetti sauce on their face, cocked eyes, and a VERY loud voice.

That fucking gomp crushed my kitten's head with his superhuman strength.